This invention relates to the field of automatic headlight control. More particularly, it relates to a control system for automatically activating a running automobile's headlights whenever the windshield wipers are operating.
In many circumstances it is desirable for the operator of an automobile to utilize the headlights to warn other drivers of his presence. Often, particularly under inclement weather conditions, a driver may find it desirable or necessary to utilize the automobile's headlights during the daytime. Unfortunately, however, many times after the driver has reached his destination he fails to turn off the headlights thereby creating the risk of running down the automobile's battery. Accordingly, a system for automatically controlling the operation of the headlights in conjunction with the activation and deactivation of the windshield wipers is highly desirable.
One approach for solving this problem is disclosed in U.S. Pat. No. 3,500,119. The disclosed system utilizes three switching relays responsive, respectively, to the operation of the wiper motor, the ignition switch, and the headlight dimmer switch for controlling the energization of the low beam headlights and tail lights. However, this approach appears to have several drawbacks. In particular, it utilizes three electromechanical relay switching devices in an attempt to achieve the desired result. Such utilization of multiple switching relays is unnecessarily complex and may have a tendency to increase the risk of failure due to component malfunction. Furthermore, the headlight control system disclosed in the '119 patent could easily cause relay R1 to operate as a shunt across the wiper motor and adversely affect or possibly render inoperative wiper motor operation at various speed settings. Also, the resistance of relay coil R1 would probably have to be carefully designed and matched to the resistance of the particular wiper motor it is to be utilized with. This design requirement is clearly not desirable, particularly when the intended usage includes operation with various motors with varying electrical characteristics mass-produced by many different manufacturers.
What is clearly needed is a simple, reliable and cost-effective system for automatically controlling the operation of a running automobile's headlights when the windshield wipers are activated.
It is accordingly a general object of the present invention to provide an automatic headlight control system which overcomes the aforementioned drawbacks.
It is a specific object of the present invention to provide an automatic headlight control system which is operatively responsive to the concurrent operation of the ignition switch and the windshield wiper switch such that the headlights are automatically turned on/off when the windshield wiper switch is activated/inactivated.
Other objects will be apparent in the following detailed description and the practice of the invention.